Thermostat



(No Model.)

H. E. THOMPSON.

THERMOSTAT.

No. 414,267. PatentedNov. 5, 1889.

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' l UNITED STATES l PATENT OEEICE.

HIRAM E. THOMPSON, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE CONSOLIDATED TEMPERATURE CONTROLLING COMPANY, OF MINNESOTA.

THERMOSTAT.

SPECIFICATION forming part of Letters Patent No. 414,267, dated November 5, 1889. Application iiled January 8, 1889.` Serial No. 295,767. (No model.)

T0 all whom t ntay/ concern:

Be it known that l, HIRAM E. THOMPSON, of Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Therinostats, of which the following is a specification.

My invention relates to improvements in thermostats particularly adapted to be used in connection with electrically-controlled motors for the regulation of heat in buildings, railway-cars, or other apartments; and it consists in a new device for adjusting the electrical contact-points of the thermostat and predetermining the degree of temperature at which a contact will be made between the bar and said points.

My invention further consists in the construction and combination hereinafter described, and particularly pointed out in the claims.

In the drawings forming a part of this specification, Figure l is a front elevation of a thermostat with my improvements applied thereto. Fig. 2 is a rear elevation of the same. Figs. 3 and 4 are details.

In the drawings, 2 represents the base of the thermostat, preferably constructed of cast metal, of any convenient form or size.

4 is a post secured to the base 2 and supporting one end of the thermostat-bar 6. This bar is free at its opposite end and constructed of two differently-expanding materials-as rubber and metal-in the ordinary manner.

8 represents a plate, preferably located vupon the under side of the base 2, and pivoted at one end to the said base by the pivot-bolt 10. Secured to this plate and moving with it are the binding-posts l2 and 14, in which are secured the contact-pins i6 and 1S. A contactspring 20, secured to the bar 6, extends between the two pins 16 and 18, and may be brought.- in contact with either of said pins. The end of the plate 8 opposite the pivot is preferably constructed with the projections or guides 24, and an eccentric 26 upon the shaft 28 is located between these projections, against which it forms bearings at opposite points upon its periphery. The eccentricshaft 28 passes through the base, and is pro- 5o vided with a knob or hand-wheel 30, by which the said shaft may be revolved. The knob is preferablyprovided with a ange 32,which rests upon the outer surface of the base. This flange is graduated upon its outer circumference to indicate, in connection with a line upon the base, the variations in the degrees of heat at which a contact will be made between the thermostat-base and the contactpins. The surface of the base and the bar 6o are adjusted so that the number on the flange opposite the line 38 will indicate the temperature at which a contact will be made between the bar G and the pin l0.

It will be seen that the divisions indicating the extremes of temperature are placed oppositely upon the iiange, and the divisions are contained wit-hin the half-circumference of the said flange. As a half-revolution of the knob will move the eccentric from the one 7o extreme to the other of its th row, the plate and posts attached thereto will be carried from one eXtreme to the other by this half-revolution. An equivalent for this device is shown in Fig. 4, in which the plate 8 is provided with 7 5 a rack S-i, and a pinion 36 is attached to the shaft 28. This pinion meshes with the rack, and as the knob is revolved the plate is partially revolved about the pivot l0, and the contact-points are changed in a manner simi- 8o lar to that already described. With this arrangement a full revolution of the knob may be obtained, and the divisions upon the flange may, if desired, cover the whole circumference.

The operation of my device is as follows: The contact-points are adjusted so that the scale on the flange of the knob indicates the degree of temperature at which the spring will come in contact with one of the contact- 9o points, so that a fall in temperature of one or two degrees will bring the spring in contact with the other contact-point. The special advantages from this construction are that the thermostat may be very accurately adjusted, and any accidental movement of the plate is prevented, as it is locked by the eccentric, and can only be moved by turning the operatingshaft on its axis.

The thermostat is particularly applicable for use with heat-regulators which employ a spring or other motor for moving the valves that control the supply of heat to the apartment in which the thermostat is located.

I claim as my invention- 1. In a thermostat, the combination, with the thermostatic bar, of a movable plate 8, carrying the contact-points and adjustably Secured to the base of the thermostat, and the rotatable shaft 28, engaging with said plate and adapted to move it laterally, substantially as described.

2. In a thermostat, the combination, with the thermostatic. bar, of the pivoted plate 8,

HIRAM E. THOMPSON.

In presence of- A. C. PAUL, J. J ESSEN. 

